Abstract Regular physical activity benefits older adults physically and mentally. However, the availability and the evidence for physical activity programs that are safe and appropriate for home-bound seniors at risk for nursing home admission are severely limited. The long-term goal of the parent R01 project is to develop a sustainable health promotion program led by home care aides that can be used by community-based organizations, such as home care agencies and state units on aging, to maintain independence among nursing home-eligible older adults living in their homes. The R01 project aims to examine the effectiveness of a safe physical activity program, led by home care aides who regularly help hard-to-reach older home care clients with housekeeping and routine personal care services in the home. The primary objective is to test whether the safe physical activity program with a built-in motivational enhancement component, performed in a seated position, preserves the function and well-being of home care clients. The secondary objective is to understand for whom the program is efficacious, the extent to which the program can reach the target population, the extent to which participants drop out of the program, the extent to which program participants maintain the behavioral change introduced by the intervention, and what the program?s cost-effectiveness is. Building on a pilot project that demonstrated the program?s feasibility in a large Medicaid home care program, this randomized controlled trial will inform future expansion of the physical activity program into real-world home care settings. This administrative supplement project will add two sub-aims to the parent grant: (1) adding measures of Alzheimer?s disease and related dementia, and (2) adapting and pilot testing the physical activity program for persons with dementia. This R01 research along with the administrative supplement project will provide evidence and guidelines for a new model of home care, which will facilitate older home care clients and their home care aides to work together to maintain or improve the function of nursing home-eligible seniors so that they can remain in the community.